Coupling devices



May 11, 1965 E. cRosBY, JR

COUPLING DEVICES Filed Aug. 28, 1962 P19/0R A197' FERR/TE INVENTOR3,183,473 CUPLING DEVICES Edward L. Crosby, Jr., Sarasota, Fla.,assigner to Electro- Mechanical Research, Inc., Sarasota, Fla., acorporation of Connecticut Filed Aug. 28, 1952, Ser, No. 219,@8 3Claims. (Cl. 339-143) This invention relates to coupling devices andmore particularly to devices adapted to carry one or more detachablecontacts for making the junctions between current-carrying conductors,the devices accomplishing at least a double function: that ofestablishing detachable connections and that of blocking the passage ofnoise and transient signals.

The problem of transient interference in audio and video circuits isfamiliar to most radio and television users. Thus when an electricrazor, a food mixer, a motor, etc., are operated in close proximity tocommunication apparatus, the quality of reception is deleteriouslyaffected. This problem becomes acute in modern aircraft and missileswhere hundreds of sensitive navigation instruments are housed in tooclose proximity to large and noisy powerconsuming devices such asservos, ignition systems, electrohydraulic actuators, gas dischargedevices, etc.

Generally, this problem was solved in one of two ways: either aradio-frequency choke was connected in series, or a filter capacitor wasconnected in parallel, with each current-carrying conductor. However,the required number of chokes or filters greatly increases the cost,volume, and weight of the communication apparatus.

Accordingly, inasmuch as most communication apparatus are connected topower supplies or other equipments and networks through connectors, itis a broad object of the present invention to provide new and improvedcoupling devices or connectors adapted to act both as coupling devicesand as noise-and-transient-signal Suppressors.

This and other apparent objects of the invention are accomplished bymaking the coupling devices insulating members `(such as matrices,sockets, cores, etc.), which carry the contacts, of magnetic ferritematerial.

The invention will be better understood by reference to the followingdescription taken in conjunction with the accompanying drawings inwhich:

FIGURE 1 shows in cross-section a typical prior-art connector couplingan energizing source to a utilization device through a noise eliminatingnetwork;

FIGURE 2 shows a simple connector of the invention;

FIGURE 3 shows a socket of a transistor constructed in accordance withthe teachings of the invention;

FIGURE 4 shows a circular type connector constructed in accordance withthe invention; and

FIGURE 5 shows a printed circuit type connector constructed inaccordance with the teachings of the invention.

Referring to FIGURE l there is shown a cross-section of a typicalprior-art connector generally designated as lil, for detachably couplingwires 11 and 12. Connector may include a metallic shell 13, aninsulating member or core 14 providing a rigid support for a female pinor contact 15 connected at 17 to wire 11, and an insulating core 18providing a rigid support for a male pin or contact 16 connected at 19to wire 12. The purpose of contacts 15 and 16 is to allow anegligible-resistance, detachable connection between wires 1.1 and 12.Cores 14, 18 merely act as insulating supports for pins 15, 16respectively. If a metal shell 13 is employed as a return path for thecurrent i flowing in wires 11 and 12, then cores 14, 1S also support thetwo half sections of the shell 13.

A typical function of connector 1i) is to detachably connect the inputline of a utilization device 26 as a radio, to the output line 27 of apower supply .28. If no noise-and-transient-signal suppression isdesired then line United States Patent O y 3,183,473 Patented May 11,1,965

Fice

l12 may be directly connected to line 2.5. On the other hand, if suchsuppression is desired then either a radiofrequency choke Sil isconnected in series with lines 12 and 25, or lines 12 and 25 aredirectly connected through a bus wire 32, and a large valued filter, asa capacitor 34, is connected between wire 32 and ground. Theradio-frequency choke Sil acts as a high impedance and the filtercapacitor 34 acts as a low impedance for the relatively high frequencynoise-and-transient signals, as is well known.

It will be appreciated that often a prior-art connector such as shown inFIGURE 1 carries tens and even hundreds of contacts and, consequently,the required number of chokes or capacitors becomes prohibitively greatfor most compact communication installations.

IIn accordance with one characteristic of this invention the need foreither radio-frequency chokes or filter capacitors is eliminated. Thisis accomplished by making at least one of the connectors insulatingmembers of magnetic ferrite. As is well known, ferrites are produced bypressing and firing methods similar to those employed in themanufacturing of porcelain. Ferrites are relatively inexpensive and wellsuited for mass production. They are surprisingly suitable for makingthe connectors insulators because they have: (l) suflicient physicalstrength and hardness required for supporting the connectors contacts;(.2) high bulk resistivity required for proper intercircuit isolation;(3) high iinpermeability to humidity and sufricient chemical inertnessboth necessary for satisfactory operation under severe environmentalconditions; and (4) a magnetic permeability required for making theconnector function like a frequency selective resistor, i.e., act asabus wire at relatively low frequencies, say below 1 to 10 megacycles,and exhibit the desired AC. resistance and impedance required fornoise-and-transient-signal suppression, at higher frequencies from 10 toabove 500 megacycles. In addition, unlike conventional chokes, theeffective inductance of the contact carrying ferrite members isrelatively low thereby avoiding undesirable interference with resonantcircuits.

Obviously the teachings of this invention are not limited to anyparticular type connector or to connectors per se. The insulatingsupport member carrying the contacts or pins of any electrical componentor device can be made of ferrite to achieve the said double function.

In the following figures the same numerals refer to similar parts. Thusin FIGURE 2 is shown in accordance with the invention a simple connectorfor detachably coupling wires 111 and 1=2 with the aid of contacts orpins 15 and 16, respectively mounted or embedded in matrices 4t), ilmade of magnetic ferrite. Each matrix, obviously, can carry a pluralityof pins suitably spaced apart. FIGURE 3 shows a typical base or socket45 of a transistor. Base d5 can be conveniently made of ferrite toaccomplish the above mentioned dou-ble function: that of connecting itsfemale pins 45 to the male pins of a suitable transistor (not shown) andthat of preventing noise, transient signals, and spurious oscillationsfrom reaching the transistors electrodes. lt will be apparent that avacuum tube socket can equally be made of ferrite. `FGURE 4 shows aconventional circular type connector, generally designated as 50,including a metallic shell 51, a core 52 for supporting the male pins53, and another core 54 for supporting the female pins 5S. ln accordancewith the invention, in the circular connector 'Sib at least one of thecores 513, 54 is made of magnetic ferrite.

ln FIGURE 5 is shown a printed circuit type connector, generallydesignated as 60, including a matrix 61 rigidly supporting iiexiblecontacts 62 for detachably coupling the printed circuit conductors 63 ofthe printed circuit board 64 to another printed circuit board or to aninter-connecting cable. The matrix 61 of the printed circuit connectoransa/irs 3. 60 is also made of magnetic ferrite to accomplish the abovementioned double function.

In operation, the invention makes use of a known phenomenon: when a buswire is surrounded by or embedded in ferrite, its A.C. resistance andimpedance are negligible only to the passage of relatively low frequencysignals, but they can be selectively made to' become appreciabie torelatively high frequency signals. By choosing different types offerrites the A.C. resistance and impedance can be selectively made torespectively assume various functions of frequency: in some applicationsit may be desired that the A1C. resistance and impedance remainsubstantially constant with frequency; in other applications, however,it may be desired that the AC. resistance or impedance either increaseor decrease with frequency. in surn, at relatively low frequencies, saybelow 1 to 1() megacycles, the coupling devices of the present inventionact in the circuits employing them as conventional coupling devices butatrelatively high frequencies, say from 10 to above 500 megacycles, thecoupling devices function essentially as frequency selective resistorsexhibiting a surprisingly low inductance thereby minimizing theundesirable interference with tuned circuits or the introduction ofphase shifts and delays. Moreover it was rst experimentally establishedand then theoretically conrrned that when the coupling devices carrymultiple contacts, an unexpected result is obtained in that there is noappreciable magnetic coupling between the contacts thereby avoiding anycrosstalk between the current carrying conductors connected to thecontacts.

It will be understood that the specific embodiments described above andillustrated in the drawings are susceptible of numerous modifications inform and detail within the scope of the invention. Gther modificationswill be readily apparent to persons skilled in the art. The particularembodiments disclosed herein, therefore, are not to be regarded asimposing any limitations whatsoever upon the scope of the followingclaims.

What is claimed is:

1 A coupling device for detachably connecting at least one end of afirst conductor to at least another end of a second conductor, saiddevice comprising:

a coupling member, said member being made at least in part of ferritefor suppressing noise signals transmitted through said conductors,

a coupling terminal mounted in said member for receiving said one end ofsaid first conductor, and

said coupling terminal being adapted for connection to said other end ofsaid second conductor, thereby detachably establishing electricalcontact between said first and second conductors.

2. The coupling device of claim l and further including another couplingmember, said other coupling member being made at least in part offerrite,

another coupling terminal mounted in said other coupling member forreceiving said other end of said second conductor, and

said coupling terminal being adapted for connection to said othercoupling terminal.

3. The coupling device of claim 2 and further including a metalliccircular shell for supporting at least one of said coupling members.

References Cited hy the Examiner UNITED STATES PATENTS 2,038,353 4/36Gardner et al 339-149 X 2,469,380 5/49 Frese 339-143 X 3,072,869 yl/63Seidel M 333--24.2

r IGSEPH D. SEERS, Primary Examiner. o runnen-r H. KAMPE, Examiner.

1. A COUPLING DEVICE FOR DETACHABLY CONNECTING AT LEAST ONE END OF AFIRST CONDUCTOR TO AT LEAST ANOTHER END OF A SECOND CONDUCTOR, SAIDDEVICE COMPRISING: A COUPLING MEMBER, SAID MEMBER BEING MADE AT LEAST INPART OF FERRITE FOR SUPPRESSING NOISE SIGNALS TRANSMITTED THROUGH SAIDCONDUCTORS, A COUPLING TERMINAL MOUNTED IN SAID MEMBER FOR RECEIVINGSAID ONE END OF SID FIRST CONDUCTOR, AND SAID COUPLING TERMINAL BEINGADAPTED FRO CONNECTION TO SAID OTHER END OF SAID SECOND CONDUCTOR,THEREBY DETACHABLY ESTABLISHING ELECTRICAL CONTACT BETWEEN SAID FIRSTAND SECOND CONDUCTORS.